Piping elbow liners

ABSTRACT

Liners useful as piping elbow liners comprising a body liner, a tangential inlet liner, and a tangential outlet liner. The tangential inlet liner and the tangential outlet liner can be removably inserted into a cavity in the body liner. The body liner can comprise two substantially-identical body section liners.

FIELD OF THE INVENTION

The present invention generally relates to apparatus for changing thedirection of a fluid flow, especially of high temperature and/or highlyabrasive fluid flows. More specifically, the present invention relatesto such apparatus which employ a protective liner for protecting anouter pipe or vessel wall from direct exposure to such high temperatureand/or highly abrasive fluid flows, for example, a refractory liner.

BACKGROUND AND SUMMARY OF THE INVENTION

In any enclosed system containing a flowing fluid, such as a pipingsystem, there is frequently a need to make directional changes in thefluid flow. Typically, standard piping elbows, also referred to asbends, are used. However, circumstances frequently exist that imposeconstraints and preclude the use of standard piping elbows. Thesecircumstances include the conveying of high temperature fluids,corrosive fluid streams, or abrasive fluid streams such as those thatare particulate-laden fluid streams. When these conditions exist, atypical solution to changing the fluid flow direction often involvesusing larger size (that is, greater diameter) piping elements lined withan appropriate refractory, corrosion-resistant, or abrasion-resistantlining.

An increase in the piping diameter requires an accompanying increase inthe turning radius of any needed bends. The increase in turning radiusin turn increases the space requirements for installing an elbow or bendneeded to make a change in the fluid flow direction. Utilizing an elbowor bend with too small of a turning radius typically causes anundesirable pressure loss.

As related in a commonly-assigned application filed concurrent with thepresent application, the inventors have addressed one or more of theabove-mentioned deficiencies in the prior art by providing a pipingelbow capable of facilitating a fluid flow direction change in a smallerspace than conventional piping elbows, without causing the largerpressure losses found when using conventional elbows in the equivalentspace. These piping elbows comprise a substantially-cylindrical bodyhaving a first end, a second end, and a substantially-constant insidediameter; a tangential inlet attached to the body near the first end ofthe body and having an inside diameter smaller than the inside diameterof the body; and a tangential outlet attached to the body near thesecond end of the body and having an inside diameter smaller than theinside diameter of the body. Typically, fluid flows linearly through thetangential inlet and enters the body. Inside the body, linear motion ofthe fluid is converted into a rotational or spiral motion. The fluid inthe body continues its spiral motion as it also moves axially throughthe body toward the tangential outlet. The fluid exits the body throughthe tangential outlet. Upon exiting through the tangential outlet,rotational or spiral motion of the fluid in the body is converted backinto linear motion.

In a preferred embodiment, the piping elbows comprise twosubstantially-identical components attached to each other. In anotherpreferred embodiment, the two substantially-identical components areremovably attached to each other so that the tangential inlet/outlet onthe first component can be oriented at any desired angle with respect tothe tangential inlet/outlet on the second component.

The present application concerns a liner which is especially adapted foruse with the above-described piping elbows, for example, in redirectingflows of high temperature and/or highly abrasive fluids, as well asmethods of making the liner. In one embodiment, liners according to thepresent invention comprise a body liner, a tangential inlet liner, and atangential outlet liner. In one preferred embodiment, the tangentialinlet liner and the tangential outlet liner are each removably insertedinto a cavity in the body liner. In another embodiment, the body sectionliner comprises two substantially-identical body section liners. Amethod of making the liner in its preferred embodiment comprisesproviding a first substantially cylindrical structure having an insidesurface and an inside diameter, providing second and third substantiallycylindrical structures which each have a first end, an inside diametersmaller than the inside diameter of the first structure and an outsidediameter, creating two cavities in the first structure which have adiameter equal to or greater than the outside diameter of thecorresponding second and third structures, shaping the first ends of thesecond and third structures to be substantially identical to the shapesof the created cavities in the first structure, and inserting the shapedfirst ends of the second and third structures into the matching cavitiesin the first structure.

DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example in the followingdrawings in which like references indicate similar elements. Thefollowing drawings disclose various embodiments of the present inventionfor purposes of illustration only and are not intended to limit thescope of the invention.

FIG. 1 shows a piping elbow having a tangential inlet and tangentialoutlet that are axially oriented in substantially-opposite directions.

FIG. 2 shows a top-down view of the piping elbow of FIG. 1.

FIG. 3 shows a top-down view of a piping elbow with a tangential inletand tangential outlet that are axially oriented at about 90 degrees toeach other.

FIG. 4 shows a top-down view of a piping elbow with a tangential inletand tangential outlet that are axially oriented in substantially thesame direction.

FIG. 5 shows a piping elbow of the type shown in FIG. 1 but which iscomprised of two substantially identical component sections, providing atangential inlet and tangential outlet that are axially oriented insubstantially-opposite directions.

FIG. 6 shows the piping elbow of FIG. 5, wherein the two componentsections have been attached to provide a tangential inlet and tangentialoutlet that are axially oriented at about 90 degrees to each other.

FIG. 7 shows the piping elbow of FIG. 5, wherein the two componentsections have been attached to provide a tangential inlet and tangentialoutlet that are axially oriented in substantially the same directions.

FIG. 8 shows an exploded view of one of two substantially-identicalpiping constructs reflected in FIGS. 5 through 7.

FIG. 9 shows an exploded view of two piping constructs of FIG. 8removably attached to each other.

FIG. 10 shows another view of a body section liner and tangential inletliner according to the present invention as shown in FIGS. 8 and 9.

FIG. 11 shows the tangential inlet liner of FIGS. 8 and 9 inserted intothe cavity of the body section liner of FIGS. 8 and 9.

FIG. 12 shows a schematic of the body section liner of FIG. 10.

FIG. 13 shows a schematic tangential inlet liner of FIG. 11.

FIG. 14 shows a cylindrically-shaped section of a liner having anelectrically conductive wire placed near the outside surface of theliner in a zigzag pattern, according to one embodiment of a method andapparatus for detecting wear in the liners of the present invention.

FIG. 15 shows a cross-sectional view of the body section liner shown inFIG. 14.

FIG. 16 shows a cylindrically-shaped section of a piping liner having anelectrically conductive wire placed near the outside surface of theliner in a spiral pattern, according to another embodiment of a methodand apparatus for detecting wear in the liners of the present invention.

FIG. 17 shows a cross-sectional view of the liner section shown in FIG.16.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the following detailed description of preferred embodiments of thepresent invention, reference is made to the accompanying Drawings, whichform a part hereof, and in which are shown by way of illustrationspecific embodiments and contexts in which the present invention may bepracticed. It should be understood that other embodiments may beutilized and changes may be made without departing from the scope of thepresent invention.

The piping elbows in which the present inventive liners are mostpreferably employed comprise a substantially-cylindrical body having afirst end and a second end and having a substantially-constant diameter;a tangential inlet attached to the body section near the first end ofthe body section and having a diameter smaller than the diameter of thebody section; and a tangential outlet attached to the body section nearthe second end of the body section and having a diameter smaller thanthe diameter of the body section. Unless specified otherwise herein, theword “diameter” will refer to the inside diameter of an article.

For purposes of the present specification the first end of the bodysection may from time to time also be referred to as the “top” of thebody, and thus the “top” of the piping elbow, while the second end maybe referred to as the “bottom” of the body and the “bottom” of thepiping elbow. While the words “top” and “bottom” may be used as a matterof convenience in the course of the present description to indicatespecific ends of the body and piping elbow, the use of the words “top”and “bottom” should not be taken to indicate or imply that the pipingelbows in which the inventive liner finds application necessarily arevertically-oriented or have a “top” or “bottom” end—the ends may be atthe same elevation.

In a piping elbow of the type shown in the drawings, fluid flowslinearly through the tangential inlet and enters the body. Inside thebody, essentially linear motion of the fluid is converted into arotational or spiral motion. The fluid in the body continues its spiralmotion as it also moves axially through the body section, toward thetangential outlet. The fluid exits the body through the tangentialoutlet. Upon existing through the tangential outlet, rotational orspiral motion of the fluid in the body is converted back into linearmotion.

FIG. 1 shows an example of such a piping elbow 100. The piping elbow 100comprises a tangential inlet 102, a body 104, and a tangential outlet106. In a typical operation of the piping elbow 100, fluid flowsessentially linearly through the tangential inlet 102, as indicated bythe arrow 108, and enters the body 104. Upon entering the body 104,linear motion of the fluid flow is converted to a spiral motion as thefluid moves axially from the tangential inlet 102 toward the tangentialoutlet 106. Upon reaching the tangential outlet 106, spiral motion istranslated back to linear motion as the fluid exits the body 104 asindicated by the arrow 110.

In order to facilitate the spiral motion of the fluid in the body,inlets and outlets according to the present invention are both smallerin diameter than the body. By tangential it is meant that the axis ofthe inlet (or outlet) does not pass through the axis of the body. Thetangential inlet and tangential outlet can also be thought of as beingoff-center in relation to the body. The tangential nature of the inletand outlet are more clearly illustrated in FIG. 2. FIG. 2 shows atop-down view of a piping elbow 200 similar to the piping elbow 100illustrated in FIG. 1. The piping elbow 200 comprises a tangential inlet202, a body 204, and a tangential outlet 206. As shown in FIG. 2, theaxis 208 of the tangential inlet 202 does not intersect with the axis210 of the body 204. If a tangential inlet were centered with respect toa body, then the axis of the tangential inlet would intersect the axisof the body. Similarly, the axis 212 of the tangential outlet 206 doesnot intersect with the axis 210 of the body 204.

Fluid enters the body 204 through the tangential inlet 202 as indicatedby the arrows 214. Inside the body 204, fluid travels toward thetangential outlet in a spiral motion as indicated by the arrows 216.Upon reaching the tangential outlet 206, fluid exits the body asindicated by the arrows 218.

The tangential inlet and tangential outlet are both smaller in diameterthan the body. For many applications, the diameter of the tangentialinlet will be about the same size as the diameter of the tangentialoutlet. Preferably, the diameter of the body is at least about 1.5 timesas large as the diameter of the tangential inlet and the diameter of thetangential outlet. More preferably, the diameter of the body is at leastabout 2 times as large as the diameter of the tangential inlet and thediameter of the tangential outlet. Preferably, the diameter of the bodysection is no more than about 3 times as large as the diameter of thetangential inlet and the diameter of the tangential outlet.

The tangential inlet and tangential outlet may be axially-oriented inany direction relative to each other. For example, in FIG. 2 thedirection of the fluid flow in the tangential inlet 202 is in theopposite direction of the fluid flow in the tangential outlet 206. Thatis, the direction of the fluid flow in the tangential inlet 202 is about180 degrees in relation to the fluid flow in the tangential outlet 206.Thus, the tangential inlet 202 is axially-oriented in the oppositedirection of the tangential outlet 206. A piping elbow having atangential inlet and a tangential outlet axially-oriented insubstantially the opposite direction can be advantageously utilized whenthe elbow is part of a piping system serving as a return, such as when aproduct of a production system is returned or recycled back into theproduction system. The tangential inlet can be at the same elevation ora different elevation than the tangential outlet depending on the needsin any application.

To facilitate the exit of the fluid flow through the tangential outlet,the tangential outlet should be positioned on the opposite side of thebody section's axis than the tangential inlet when the inlet and outletare axially-oriented in the opposite direction. For example, in thetop-down view of piping elbow 200 shown in FIG. 2 the axis 208 of thetangential inlet 202 appears to the left of the body's axis 210 and theaxis 212 of the tangential outlet 206 appears to the right of the body'saxis 210. The positioning of the tangential inlet 202 to the left of thebody's axis 210 causes the fluid flow in the piping elbow 200 to spiralin a clockwise motion as indicated by the arrows 216. As the fluid flowcontinues to spiral it moves axially through the body 204 from thetangential inlet 202 to the tangential outlet 206. As the fluid flowreaches the tangential outlet 206, the fluid flow is moving in thedirection needed to exit through the tangential outlet 206 as indicatedby the arrows 220 and 218. The tangential inlet 202 and the tangentialoutlet 206 can in this circumstance be described as being “rotationallyaligned.” If on the other hand, the tangential outlet 206 had beenpositioned directly underneath the tangential inlet 202 such that bothaxis 208 and 212 were positioned to the left of the body's axis 210,then as the fluid flow reached the tangential outlet 206 it would not bemoving in the same direction as needed to exit the tangential outlet206.

FIG. 3 and FIG. 4 illustrate other examples of piping elbows wherein thetangential inlet and tangential outlet are rotationally aligned. In FIG.3, the piping elbow 300 comprises a tangential inlet 302, a body 304,and a tangential outlet 306, wherein the tangential inlet 302 and thetangential outlet 306 are rotationally aligned and are axially orientedat about 90 degrees to each other. In FIG. 4, the piping elbow 400comprises a tangential inlet 402, a body 404, and a tangential outlet406, wherein the tangential inlet 402 and the tangential outlet 406 arerotationally aligned and are axially oriented in substantially the samedirection.

Piping elbows as illustrated in FIGS. 1-4 can be manufactured as onesolid piece as shown in FIG. 1 or, more preferably, can be manufacturedin parts that can be assembled to form the piping elbow. In FIG. 5, thepiping elbow 500 comprises a tangential inlet 502, a body assembled fromtwo body sections 504 and 505, and a tangential outlet 506, wherein thetangential inlet 502 and the tangential outlet 506 are rotationallyaligned and are axially oriented in substantially the oppositedirection. Preferably, tangential inlet 502 and first body section 504comprise a single continuous piece and tangential outlet 506 and secondbody section 505 comprise a second single continuous piece. The body ofthe piping elbow 500 is assembled by attaching the flange 518 of thefirst body section 504 to the flange 520 of the second body section 505in conventional manner, for example by bolting flanges 518 and 520together. The top 514 of the first body section 504 is attached to thefirst body section 504 and the bottom 516 of the second body section 505is attached to the second body section 505. The first body section 504and the second body section 505 can be separated after use so that theinterior of the body can be inspected and cleaned, if necessary.Similarly, the top 514 and bottom 516 are removable so that the interiorof the body can be inspected and cleaned as needed. Additionally, thepiping elbow 500 can be removed from the rest of the piping system tofacilitate inspection, cleaning, repair, replacement, etc. by separatingflange 522 from flange 524 and separating flange 526 from flange 528.

Alternate configurations are also possible. For example, the top 514and/or bottom 516 of body sections 504 and 505 respectively may bepermanently attached instead of removably attached as described above.The top 514 and/or bottom 516 may be permanently attached in any waysuitable for the particular application. For example, the top 514 and/orbottom 516 can be manufactured as one continuous component along withbody-section 504 and/or body-section 505.

Most preferably, for simplicity and ease of manufacture the bodysections 504 and 505 are substantially identical to one another, andremovably attached via flanges 518 and 520 in a reverse mirror-imagerelationship. Thus, in FIG. 5 the piping elbow 500 can be separated intotwo substantially-identical components by separating flange 518 fromflange 520. The first substantially-identical component comprises bodysection 504, tangential inlet 502, and top 514. The secondsubstantially-identical component comprises body section 505, tangentialoutlet 506, and bottom 516. FIGS. 5-7 illustrate another advantage ofpiping elbows that comprise two substantially-identical components. Thatis, the bottom component can be oriented at a selected degree relativeto the top component to provide a desired redirection of the fluid flowin moving from the tangential inlet through the body and out through thetangential outlet. For example, FIG. 6 shows the piping elbow 500 ofFIG. 5 with the bottom component at an angle of approximately 90 degreesrelative to the top component. That is, piping elbow 600 of FIG. 6comprises the exact same components of piping elbow 500 except that thebottom component is rotated approximately 90 degrees. Similarly, FIG. 7shows piping elbow 700 comprising the exact same components of pipingelbow 500 except that the bottom component is rotated approximately 180degrees.

Piping elbows as illustrated and described above may further includecooling jackets. Cooling jackets are known in the art for coolingmaterials inside vessels or piping systems. For example, piping elbow500 comprises a cooling jacket. As shown best in FIG. 5, both the firstbody section 504 and second body section 505 of the piping elbow 500comprise a cooling jacket that includes a water inlet and water outlet,in the case of body section 504 being inlet 508 and outlet 510. Thewater inlet for body section 505, which is symmetric to water inlet 508and in the same relationship to outlet 512 as inlet 508 is to outlet510, is not shown.

Piping elbows as described and shown are particularly well-served inhandling high temperature and/or highly abrasive fluids by the use ofliners according to the present invention. For example, ceramic linerscan be advantageously utilized with piping elbows such as piping elbow500 of FIG. 5 in the context of a TiO₂ production process. After theburner section or oxidation section in a TiO₂ production process, theTiO₂ is carried by the process gases through a cooling section. Thecooling section is both a highly abrasive environment and a hightemperature environment. It is not unusual for the temperature of thefluid stream comprising TiO₂ and process gases to vary between 400° F.(204.44° C.) and 1400° F. (760° C.). Piping elbows with ceramic linerscan be advantageously utilized in this cooling section of a TiO₂production process.

In one embodiment, liners according to the present invention comprise abody liner, a tangential inlet liner, and a tangential outlet liner. Ina preferred embodiment, the tangential inlet liner and the tangentialoutlet liner have substantially the same shape. That is, the tangentialinlet liner and the tangential outlet liner are substantially identical.The body liner may comprise a single continuous component or maycomprise multiple section liners. In a preferred embodiment, the bodyliner comprises two substantially-identical body section liners. Each ofthe two substantially-identical body section liners has a cylindricalshape that is open at one end and closed at the other end. The closedend can be closed by removably attaching an end to the body sectionliner or by manufacturing the body section liner as one continuous piecehaving a closed end. In one embodiment of the present invention, atleast one body section liner has a removably attached end functioning aseither a top or bottom of the liner, which can be removed to to inspector clean the inside of the body section liner.

FIG. 8 shows an exploded view of a component 800, which is one of twosubstantially-identical components that can be removably attached toeach other to form a piping elbow as described above. The component 800is similar to the top component shown in FIG. 5 and comprises a bodysection 804, a tangential inlet 802, and a top 814. It should be notedthat if component 800 were used as a bottom component instead of a topcomponent, then the tangential inlet 802 would function as a tangentialoutlet. Component 800 further comprises a tangential inlet liner 806, abody section liner 808, and a top liner 810. During the process ofputting component 800 together, the body section liner 808 is insertedinto the body section 804 and then the tangential inlet liner 806 isinserted into the tangential inlet 802 such that the tangential inletliner 806 fits into the cavity 812 in the body section liner 808. Thetangential inlet liner 806 and the cavity 812 are shaped such that theedges of the tangential inlet liner 806 line up with the edges of thecavity 812. Thus, the shape of the cavity 812 in the body section liner808 is substantially identical to the shape of the inserted end of thetangential inlet liner 806. The construction of component 800 isfinished by placing the top liner 810 onto the body section liner 808,placing insulation 816 onto the top liner 810, placing a gasket 818 ontop of the body section 804, applying a gasket sealer 820 on top of thegasket 818, and then attaching the top 814 to the body section 804. InFIG. 8, the top 814 is removably attached to the body section 804 bybolting the top 814 to the body section 804. FIG. 9 shows an explodedview of two components 800 removably attached to each other to form apiping elbow.

FIGS. 10-11 illustrate how tangential inlet liners and tangential outletliners fit into a cavity of either a body liner or a body section linerto form a liner joint. FIG. 10 shows the tangential inlet liner 806, thebody section liner 808, and the cavity 812 of FIGS. 8 and 9. As shown inFIG. 10, the shape of the inserted end of the tangential inlet 806 issubstantially identical to the shape of the cavity 812 in the bodysection liner 808. FIG. 11 shows the tangential inlet liner 806 insertedinto the cavity 812 of the body section liner 808 forming a linercomponent 1100 suitable for use in a first component of a piping elbow.The point at which an inlet or outlet is inserted into the cavity of abody liner or body section liner may be referred to herein as a linerjoint.

The cavity in a body liner or body section liner of the presentinvention can be created by removing a plug from a cylindrical piece oflining material. Ceramic pieces of lining material may be purchased fromCeramic Protection Corporation, for example. To remove the plug, theintersection of the inlet (or outlet) axis with the body is located.Projecting along this axis, a plug is removed that is approximatelyequal in diameter to the outside diameter of the inlet (or outlet) to beinserted plus any required tolerances. The plug is made to a depth suchthat the edge of the inlet (or outlet) liner is aligned with theinternal surface of the body liner. FIG. 12 shows a schematic thatillustrates a body section liner 1200 according to the presentinvention. The body section liner 1200 has an outside diameter 1202 of13½ inches (34.29 cm), an inside diameter 1204 of 12 inches (30.48 cm),and a height 1206 of 17½ inches (44.45 cm). The radius 1208 of thecavity 1210 is 4{fraction (13/16)} inches (12.22 cm) with the distance1212 from the end 1214 of the body section liner 1200 to the axis 1216of the cavity 1210 being 5¾ inches (14.61 cm). The distance 1218 fromthe axis 1216 of the cavity 1210 to the outside edge of the body sectionliner 1200 is 4¾ inches (12.07 cm).

Tangential inlet liners and tangential outlet liners also can be createdby removing a plug from a cylindrical piece of lining material. Theinlet and outlet liners can be created by removing a cylindrical plughaving a diameter approximately the same diameter as the inside diameterof the body liner into which the inlet or outlet liner is to beinserted. FIG. 13 shows a schematic that illustrates a tangential inlet(or outlet) liner 1300 having an outside diameter 1302 of 9½ inches(24.13 cm), an inside diameter 1304 of 8 inches (20.32 cm), and a height(or length) 1306 of 12 inches (30.48 cm). As illustrated in FIG. 13,tangential inlet liner 1300 has a cylindrical shape having a height 1306of 12 inches (30.48 cm) and an outside diameter 1302 of 9½ inches (24.13cm). The cylindrical shape of tangential inlet liner 1300 has acylindrical plug removed with a radius 1308 of 6 inches (15.24 cm)removed from the end of the tangential inlet liner 1300. The axis 1310of the cylindrical plug is a distance 1312 of 2 inches (5.08 cm) fromthe axis 1314 of the tangential inlet liner 1300 at its closest point.It should be noted that the radius 1308 of the removed cylindrical plug(that is, 6 inches (15.24 cm)) matches the inside diameter 1204 (thatis, 12 inches (30.48 cm)) of the body liner 1200.

Liners of the present invention have several advantages over liners usedin the prior art. When refractory brick or tile liner systems are usedin process lines or equipment as is known in the art, the linermaterials are typically bonded in place by gluing or grouting. Onceinstalled, demolition of the liner system is necessary whenever theliner system must be removed. Bricking and demolition of the linersystem are time-consuming and require fresh material to be installedevery time. Liners according to the present invention, on the otherhand, allow the liner system in certain applications to be installed andremoved repeatedly without damaging the liner materials.

Straight piping lines of the prior art offer the opportunity to insertpre-cast liner sections. However, these liner sections are still usuallybonded in place to keep the liner from moving out of position or fallingout of the body. Lining a junction such as a tee or a vessel inlet witha vessel body typically requires some type of locating, alignment, orlocking method or device. In many cases, this is done by grouting orbonding the parts in place. Once that is done, removal is difficult orimpossible without breakage of the liner system. Liners of the presentinvention provide a joint design that aligns and holds the parts of theliner in place with respect to one another, requiring little or nogrouting or bonding to maintain the integrity of the joint. That is,once a body liner is inserted into the body of a piping elbow in keepingwith FIGS. 8-13, for example, the insertion of a tangential inlet linerand a tangential outlet liner into the cavity of the body liner holdsthe body liner in place with little or no bonding. Similarly, if thetangential inlet liner and tangential outlet liner are removed, the bodyliner can be removed for inspection or replacement. In this manner, thetangential inlet liner and the tangential outlet liner are said to beremovably inserted into the cavity of the body liner and the body lineris said to be removably inserted into the body of a piping elbow.

Piping liners of the present invention are preferably utilized withvarious methods for detecting wear in the liner. One such method (asdescribed and claimed in a commonly-assigned, concurrently-filedapplication) utilizes an electrically conductive wire placed on theoutside surface of the liner relative to the flowing fluid. Theelectrical resistance of the wire is periodically measured to determinewhether the wire has worn through. If the wire is intact it will have arelatively low electrical resistance. However, if the liner is wornthrough, the abrasive environment that caused the liner to wear throughwill, in all likelihood, also cause the wire to wear through and becomediscontinuous. If the wire is worn through, then the electricalresistance in the wire will be extremely high (essentially infinite).Thus, by measuring the electrical resistance in the electricallyconductive wire, one can determine whether the wire, and therefore theliner, has worn through.

The electrically conductive wire can also be placed near the outsidesurface of the liner to determine when a significant amount of wear hasoccurred, short of complete wear-through of the liner. In a like manner,a plurality of independent electrically conductive wires can be placedin the liner at varying distances from the fluid and the resistances ofthese individually measured to assess wear rate of the liner.

An electrically conductive wire can be placed near the outside surfaceof a liner, for example, by building the wire into the liner. An exampleis provided in FIGS. 14 and 15. FIG. 14 shows an electrically conductivewire 1402 placed in a zigzag pattern near the outside surface 1404 of acylindrically-shaped section of a piping liner 1400. FIG. 15 shows across-sectional view of the liner 1400 that illustrates the wire 1402 isplaced inside the liner 1400, and therefore, near the outside surface1404 of the liner 1400. Preferably, the wire 1402 is placed closer tothe outside surface 1404 of the liner 1400 than the inside surface 1406of the liner 1400.

FIGS. 16 and 17 illustrate another example of how an electricallyconductive wire can be placed near the outside surface of a liner. FIG.16 shows a cylindrically-shaped section of a piping liner 1600 having anelectrically conductive wire 1602 placed near the outside surface 1604of the liner 1600 in a spiral pattern. The wire 1602 is placed in agroove 1606 that has been created in the outside surface 1604 of theliner. The groove 1606 can be created in any suitable manner.Preferably, the depth of the groove 1606 is chosen such that theelectrically conductive wire 1602 is closer to the outside surface 1604of the liner 1600 than the inside surface 1608 of the liner 1600 whenplaced in the groove 1606. The groove 1606 in liner 1600 is spiralshaped, but could be any shape suitable for the application, such as azigzag shape similar to the zigzag pattern shown in FIG. 14. The pipingliner 1600 can be a section of a prior art liner or a section of a lineraccording to the present invention such as a body section liner.

An alternative to the use of electrically conductive wires would be touse temperature measuring devices, for example, a thermocouple, in orderto estimate the amount of wear in the liner. For example, if a linedpiping construct is used in an application where high-temperature fluidsare involved, a temperature measuring device can be advantageouslyplaced on or near the outside surface of the liner. If the liner hasheat insulating properties (such as exhibited by a liner made of aceramic material) then the device over time will detect a graduallyincreasing temperature as the liner wears away and less insulating linermaterial separates the device from the high-temperature fluid.Monitoring the temperature detected over time allows the amount of wearon the liner to be estimated. The detected temperature at which a lineris sufficiently worn to be replaced will depend on the temperature ofthe fluid in contact with the liner, the insulating properties of theliner, and the thickness of the liner material between the temperaturemeasuring device and the fluid. However, a suitable temperature for agiven application can be determined without undue experimentation byperiodically removing a liner and visually inspecting the amount of wearand noting the temperature detected at the time the liner is removed.Once the wear is sufficient to warrant replacement of the liner, thecorresponding temperature can be noted. From that point on, new linersof the same insulating material and thickness can be inserted and notremoved until this temperature is detected or closely approached.

In one embodiment, a wire thermocouple is advantageously utilized as thetemperature measuring device. As is known in the art, a thermocouple canconsist of two dissimilar metals joined so that a potential differencegenerated between the points of contact is a measure of the temperaturedifference between the points. In a preferred embodiment, the wirethermocouple is a type J or K thermocouple. The wire thermocouple can beplaced on or near the outside surface of the liner in the same mannerthat the electrically conductive wire described above is place and isillustrated in FIGS. 14-17. In another preferred embodiment, the wirethermocouple is also electrically conductive, such that a break in thewire thermocouple can be detected by measuring the electrical resistanceof the electrically conductive wire thermocouple in the same manner thatthe electrical resistance is measured in the electrically conductivewire as described above.

While the present invention has been described in detail with respect tospecific embodiments thereof, it will be appreciated that those skilledin the art, upon attaining an understanding of the foregoing, mayreadily conceive of alterations to, variations of and equivalents tothese embodiments. Accordingly, the scope of the present inventionshould be assessed as that of the appended claims and by equivalentsthereto.

1. A method for making a liner joint of a refractory,corrosion-resistant and/or abrasion-resistant lining, comprising thesteps of: providing a first substantially cylindrical structure of theliner material having an inside surface and an inside diameter;providing a second substantially cylindrical structure of the linermaterial having a first end, having an inside diameter smaller than theinside diameter of the first structure, and having an outside diameter;creating a cavity in the first structure having a diameter equal to orlarger than the outside diameter of the second structure; shaping thefirst end of the second structure to be substantially identical to theshape of the created cavity; and inserting the shaped first end of thesecond structure into the created cavity of the first structure.
 2. Amethod according to claim 1, wherein the created cavity is off-centersuch that the inserting step forms a tangential inlet or tangentialoutlet with respect to a flow of fluids in the first structure.
 3. Amethod for making a liner joint of a refractory, corrosion-resistantand/or abrasion-resistant lining, comprising the steps of: providing afirst substantially cylindrical structure of the liner material havingan inside surface and an inside diameter; providing second and thirdsubstantially cylindrical structures of the liner material, eachstructure having a first end, an inside diameter smaller than the insidediameter of the first structure and an outside diameter; creating twocavities in the first structure, each created cavity having a diameterequal to or larger than the outside diameter of the second structure;shaping the first ends of the second and third structures to besubstantially identical to the shapes of the created cavities; andinserting each shaped first end into a created cavity.
 4. A methodaccording to claim 3, wherein the created cavities are off-center suchthat the inserting step forms a tangential inlet and a tangential outletwith respect to a flow of fluids in the first structure.
 5. A lined pipeor vessel, including: a) a liner joint of a refractory,corrosion-resistant and/or abrasion-resistant material, which jointcomprises a substantially cylindrical body section having an insidediameter, and a tangential inlet or tangential outlet inserted into acavity in the body section and having an inside diameter smaller thanthe body section's inside diameter; and b) a pipe or vessel in which theliner joint is placed, characterized in that neither the body sectionnor the tangential inlet or outlet are joined to the pipe or vessel. 6.A lined pipe or vessel, including: a) a liner joint of a refractory,corrosion-resistant and/or abrasion-resistant material, which jointcomprises: a substantially cylindrical body section having an insidediameter, a tangential inlet inserted into a first cavity in the bodysection and having an inside diameter smaller that the body's insidediameter, and a tangential outlet inserted into a second cavity in thebody section and having an inside diameter smaller that the body'sinside diameter; and b) a pipe or vessel in which the liner joint isplaced, characterized in that none of the body section, tangential inletand tangential outlet are joined to the pipe or vessel.
 7. A method formaking a liner joint of a refractory, corrosion-resistant and/orabrasion-resistant lining, comprising the steps of: providing a firstsubstantially cylindrical structure of the liner material having aninside surface and an inside diameter; providing second and thirdsubstantially cylindrical structures of the liner material, eachstructure having a first end, an inside diameter smaller than the insidediameter of the first structure and an outside diameter; creating afirst cavity in the first structure having a diameter equal to or largerthan the outside diameter of the second structure; creating a secondcavity in the first structure having a diameter equal to or larger thanthe outside diameter of the third structure; shaping the first end ofthe second structure to be substantially identical to the shape of thecreated first cavity; shaping the first end of the third structure to besubstantially identical to the shape of the created second cavity;inserting the shaped first end of the second structure into the createdfirst cavity; and inserting the shaped first end of the third structureinto the created second cavity.
 8. A method according to claim 7,wherein the created cavities are off-center such that the inserting stepforms a tangential inlet and a tangential outlet with respect to a flowof fluids in the first structure.
 9. A method according to claim 7,wherein the creating steps are performed by removing plugs from thefirst structure.
 10. A method according to claim 7, wherein the shapingsteps are performed by removing plugs from the second structure
 11. Amethod according to claim 1, wherein the creating step is performed byremoving a plug from the first structure.
 12. A method according toclaim 1, wherein the shaping step is performed by removing a plug fromthe second structure.
 13. A method according to claim 3, wherein thecreating step is performed by removing plugs from the first structure.14. A method according to claim 3, wherein the shaping step is performedby removing plugs from the second structure.
 15. A lined pipe or vesselaccording to claim 5, wherein the tangential inlet or tangential outletis removably inserted.
 16. A lined pipe or vessel according to claim 6,wherein the tangential inlet and tangential outlet are removablyinserted.